246 research outputs found

    Freshwater Testate Amoebae (Arcellinida) Response to Eutrophication as Revealed by Test Size and Shape Indices

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    We review the potential for applying traits-based approaches to freshwater testate amoeba, a diverse protist group that are abundant in lakes and are valuable ecological indicators. We investigated the efficacy of geometric morphometric analysis to define Arcellinida test size and shape indices that could summarize freshwater testate amoeba community dynamics along a temporal gradient of eutrophication in Loch Leven, Scotland (United Kingdom). A cluster analysis of test size and shape indices yielded three clusters, each dominated by a single shape: elongate, spherical and ovoid. When plotted stratigraphically, we observed increases in spherical tests, decreases in elongate tests and shrinking of test size coeval with eutrophication in Loch Leven. Decreases in the elongate cluster may reflect benthic conditions with reduced oxygen levels, while increases in the spherical cluster are likely associated with an expanding macrophyte community that promoted pelagic and epibiotic life habits. Shrinking of test size may be a stress response to eutrophication and/or warming temperatures. Tracking community dynamics using test size and shape indices was found to be as effective as using species-based approaches to summarize key palaeolimnological changes, with the added benefits of being free from taxonomic bias and error. The approach thus shows significant potential for future studies of aquatic community change in nutrient impacted lakes

    Coronary artery height differences and their effect on fractional flow reserve

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    Background: Fractional flow reserve (FFR) uses pressure-based measurements to assess the severityof a coronary stenosis. Distal pressure (Pd) is often at a different vertical height to that of the proximalaortic pressure (Pa). The difference in pressure between Pd and Pa due to hydrostatic pressure, mayimpact FFR calculation.Methods: One hundred computed tomography coronary angiographies were used to measure heightdifferences between the coronary ostia and points in the coronary tree. Mean heights were used to calculate the hydrostatic pressure effect in each artery, using a correction factor of 0.8 mmHg/cm. Thiswas tested in a simulation of intermediate coronary stenosis to give the “corrected FFR” (cFFR) andpercentage of values, which crossed a threshold of 0.8.Results: The mean height from coronary ostium to distal left anterior descending (LAD) was +5.26 cm,distal circumflex (Cx) –3.35 cm, distal right coronary artery-posterior left ventricular artery (RCA-PLV)–5.74 cm and distal RCA-posterior descending artery (PDA) +1.83 cm. For LAD, correction resulted in a mean change in FFR of +0.042, –0.027 in the Cx, –0.046 in the PLV and +0.015 in the PDA. Using 200 random FFR values between 0.75 and 0.85, the resulting cFFR crossed the clinical treatmentthreshold of 0.8 in 43% of LAD, 27% of Cx, 47% of PLV and 15% of PDA cases.Conclusions: There are significant vertical height differences between the distal artery (Pd) and its point of normalization (Pa). This is likely to have a modest effect on FFR, and correcting for this results in a proportion of values crossing treatment thresholds. Operators should be mindful of this phenomenon when interpreting FFR values

    Impact of point-of-care pre-procedure creatinine and eGFR testing in patients with ST segment elevation myocardial infarction undergoing primary PCI: The pilot STATCREAT study

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    Background: Contrast-induced acute kidney injury (CI-AKI) is a recognised complication during primary PCI that affects short and long term prognosis. The aim of this study was to assess the impact of point-of-care (POC) pre-PPCI creatinine and eGFR testing in STEMI patients. Methods 160 STEMI patients (STATCREAT group) with pre-procedure POC testing of Cr and eGFR were compared with 294 consecutive retrospective STEMI patients (control group). Patients were further divided into subjects with or without pre-existing CKD. Results: The incidence of CI-AKI in the whole population was 14.5% and not different between the two overall groups. For patients with pre-procedure CKD, contrast dose was significantly reduced in the STATCREAT group (124.6 ml vs. 152.3 ml, p = 0.015). The incidence of CI-AKI was 5.9% (n = 2) in the STATCREAT group compared with 17.9% (n = 10) in the control group (p = 0.12). There was no difference in the number of lesions treated (1.118 vs. 1.196, p = 0.643) or stents used (1.176 vs. 1.250, p = 0.78). For non-CKD patients, there was no significant difference in contrast dose (172.4 ml vs. 158.4 ml, p = 0.067), CI-AKI incidence (16.7% vs. 13.4%, p = 0.4), treated lesions (1.167 vs. 1.164, p = 1.0) or stents used (1.214 vs. 1.168, p = 0.611) between the two groups. Conclusions: Pre-PPCI point-of-care renal function testing did not reduce the incidence of CI-AKI in the overall group of STEMI patients. In patients with CKD, contrast dose was significantly reduced, but a numerical reduction in CI-AKI was not found to be statistically significant. No significant differences were found in the non-CKD group

    New genetic loci implicated in fasting glucose homeostasis and their impact on type 2 diabetes risk.

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    Levels of circulating glucose are tightly regulated. To identify new loci influencing glycemic traits, we performed meta-analyses of 21 genome-wide association studies informative for fasting glucose, fasting insulin and indices of beta-cell function (HOMA-B) and insulin resistance (HOMA-IR) in up to 46,186 nondiabetic participants. Follow-up of 25 loci in up to 76,558 additional subjects identified 16 loci associated with fasting glucose and HOMA-B and two loci associated with fasting insulin and HOMA-IR. These include nine loci newly associated with fasting glucose (in or near ADCY5, MADD, ADRA2A, CRY2, FADS1, GLIS3, SLC2A2, PROX1 and C2CD4B) and one influencing fasting insulin and HOMA-IR (near IGF1). We also demonstrated association of ADCY5, PROX1, GCK, GCKR and DGKB-TMEM195 with type 2 diabetes. Within these loci, likely biological candidate genes influence signal transduction, cell proliferation, development, glucose-sensing and circadian regulation. Our results demonstrate that genetic studies of glycemic traits can identify type 2 diabetes risk loci, as well as loci containing gene variants that are associated with a modest elevation in glucose levels but are not associated with overt diabetes

    The Evolution of Compact Binary Star Systems

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    We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

    Policymakers\u27 experience of a capacity-building intervention designed to increase their use of research: A realist process evaluation

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    Background: An intervention’s success depends on how participants interact with it in local settings. Process evaluation examines these interactions, indicating why an intervention was or was not effective, and how it (and similar interventions) can be improved for better contextual fit. This is particularly important for innovative trials like Supporting Policy In health with Research: an Intervention Trial (SPIRIT), where causal mechanisms are poorly understood. SPIRIT was testing a multi-component intervention designed to increase the capacity of health policymakers to use research. Methods: Our mixed-methods process evaluation sought to explain variation in observed process effects across the six agencies that participated in SPIRIT. Data collection included observations of intervention workshops (n = 59), purposively sampled interviews (n = 76) and participant feedback forms (n = 553). Using a realist approach, data was coded for context-mechanism-process effect configurations (retroductive analysis) by two authors. Results: Intervention workshops were very well received. There was greater variation of views regarding other aspects of SPIRIT such as data collection, communication and the intervention’s overall value. We identified nine inter-related mechanisms that were crucial for engaging participants in these policy settings: (1) Accepting the premise (agreeing with the study’s assumptions); (2) Self-determination (participative choice); (3) The Value Proposition (seeing potential gain); (4) ‘Getting good stuff’ (identifying useful ideas, resources or connections); (5) Self-efficacy (believing ‘we can do this!’); (6) Respect (feeling that SPIRIT understands and values one’s work); (7) Confidence (believing in the study’s integrity and validity); (8) Persuasive leadership (authentic and compelling advocacy from leaders); and (9) Strategic insider facilitation (local translation and mediation). These findings were used to develop tentative explanatory propositions and to revise the programme theory. Conclusion: This paper describes how SPIRIT functioned in six policy agencies, including why strategies that worked well in one site were less effective in others. Findings indicate a complex interaction between participants’ perception of the intervention, shifting contextual factors, and the form that the intervention took in each site. Our propositions provide transferable lessons about contextualised areas of strength and weakness that may be useful in the development and implementation of similar studies

    Mortality and disability-adjusted life years in North Africa and Middle East attributed to kidney dysfunction : a systematic analysis for the Global Burden of Disease Study 2019

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    The authors would like to thank the hard work of the staff of the Institute for Health Metrics and Evaluation (IHME) for providing the best possible epidemiologic estimation of diseases in almost all regions and countries of the world, trying to reduce and eliminate poverty of knowledge and information about the diseases globally. Also, the core team authors sincerely thank all the collaborators of the GBD 2019 study who contributed to this study by providing data or a precise review of the manuscript. Publisher Copyright: © The Author(s) 2023. Published by Oxford University Press on behalf of the ERA. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Peer reviewe

    REPAIRS Delphi: A UK and Ireland Consensus Statement on the Management of Infected Arterial Pseudoaneurysms Secondary to Groin Injecting Drug Use

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    \ua9 2024 The Author(s)Objective: Consensus guidelines on the optimal management of infected arterial pseudoaneurysms secondary to groin injecting drug use are lacking. This pathology is a problem in the UK and globally, yet operative management options remain contentious. This study was designed to establish consensus to promote better management of these patients, drawing on the expert experience of those in a location with a high prevalence of illicit drug use. Methods: A three round modified Delphi was undertaken, systematically surveying consultant vascular surgeons in the UK and Ireland using an online platform. Seventy five vascular surgery units were invited to participate, with one consultant providing the unit consensus practice. Round one responses were thematically analysed to generate statements for round two. These statements were evaluated by participants using a five point Likert scale. Consensus was achieved at a threshold of 70% or more agreement or disagreement. Those statements not reaching consensus were assessed and modified for round three. The results of the Delphi process constituted the consensus statement. Results: Round one received 64 (86%) responses, round two 59 (79%) responses, and round three 62 (83%) responses; 73 (97%) of 75 units contributed. Round two comprised 150 statements and round three 24 statements. Ninety one statements achieved consensus agreement and 15 consensus disagreement. The Delphi statements covered sequential management of these patients from diagnosis and imaging, antibiotics and microbiology, surgical approach, wound management, follow up, and additional considerations. Pre-operative imaging achieved consensus agreement (97%), with computerised tomography angiography being the modality of choice (97%). Ligation and debridement without arterial reconstruction was the preferred approach at initial surgical intervention (89%). Multidisciplinary management, ensuring holistic care and access to substance use services, also gained consensus agreement. Conclusion: This comprehensive consensus statement provides a strong insight into the standard of care for these patients
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